1. Technical Field
The present disclosure relates to a transmission that enables prevention of torque interruption in a gear shift.
2. Description of Related Art
Transmissions that enable prevention of torque interruption in a gear shift. In a transmission disclosed in Published Japanese Translation of PCT Application No. 2006-525479, a shift fork moves disk springs, whereby engagement bar sets move to the shift gear side. Each disk spring includes three arms. In other words, in JP-A-2006-525479, the disk springs and the engagement bar sets are formed of different members, and a driving force of the shift fork is transmitted to the engagement bar sets through the disk springs (the three arms).
In a transmission disclosed in Japanese Patent Application Publication No. 2013-210085, a shift fork moves detent mechanisms, whereby keys move to the shift gear side. Each detent mechanism includes a groove portion formed in the key, a ball disposed in the groove portion, and biasing means for pressing the ball against the groove portion. In other words, in JP 2013-210085 A, the detent mechanisms (the ball and the biasing means) and the keys are formed of different members, and a driving force of the shift fork is transmitted to the keys through the detent mechanisms (the ball and the biasing means).
In the bar sets or the keys, respective engagement portions are formed. A gear shift is made as a result of the bar sets or the keys (engagement portions) moving in an axis direction and the engagement portions engaging with dogs of a shift gear. In the transmissions disclosed in JP-A-2006-525479 and JP 2013-210085 A, the shift fork (shift member) moves the bar sets or the keys via the disk springs or the detent mechanisms. In other words, the transmissions disclosed in JP-A-2006-525479 and JP 2013-210085 A, the shift fork does not directly move the bar sets or the keys with the respective engagement portions formed therein. Thus, there is a delay in movement of the engagement portions relative to movement of the shift fork.
In the transmissions disclosed in JP-A-2006-525479 and JP 2013-210085 A, even if the shift fork is driven when the engagement portions and the dogs are in proper relative positions in a rotation direction, the engagement portions move in retard of the shift fork, which may result in failure of the engagement portions and the dogs to engage with each other properly and thus may result in frequent collision between edges of the engagement portions and edges of the dogs. In other words, a delay of movement of the engagement portions relative to movement of the shift fork causes a gear shift lag due to a retry of engagement or decrease in durability of the engagement portions and the dogs due to frequent collision of these members.